This is a domain of unknown function that is associated with a number of different protein families. It is found in Rtt106p, which is a histone chaperone involved in heterochromatin-mediated silencing [(PUBMED:16157874)]. It is also found in genes annotated as metallopeptidases and various FACT complex subunits.

Rtt106p is a histone chaperone involved in heterochromatin-mediated silencing.

Proc Natl Acad Sci U S A. 2005; 102: 13410-5

Display abstract

Epigenetic inheritance of heterochromatin structure is an important cellularprocess whose mechanism remains elusive. In this article, we describe theidentification of nine enhancers of the silencing defect of a Saccharomycescerevisiae-PCNA mutant by screening a library of approximately 4,700 viable yeastdeletion mutants. Of the nine mutants identified, six (hir1, hir3, sas2, sas4,sas5, and sir1) were previously known to reduce silencing synergistically with a mutation in Cac1p, the large subunit of chromatin assembly factor 1 (CAF-1). The predicted gene products that are affected in three other mutants (nam7, msh2, andrtt106) have not been implicated previously in silencing. Characterization of thertt106Delta allele revealed that it synergistically reduced heterochromatinsilencing when combined with a mutation in Cac1p but not with a mutation in Asf1p(a histone H3 and H4 chaperone). Moreover, Rtt106p interacted with histones H3and H4 both in vitro and in vivo, and it displayed a nucleosome assembly activityin vitro. Furthermore, Rtt106p interacts with CAF-1 physically through Cac1p.These biochemical and genetic data indicate that Rtt106p is a previouslyuncharacterized histone chaperone connecting S phase to epigenetic inheritance.